Internal combustion engine



May 31 1932. M. B. JACKSON INTERNAL COMBUSTION ENGINE Filed March 18,1930 LNVEN'I'UR.

Patented May 31, 1932 UNITED STATES,

PATENT KQFF-ICIEF' 5 MAUNsELLB. JAcKsoN, or TonoN'ro, 'oN'rARro,cnNnnAjnssreNon T0 ALBERT-E. DYMENT, JAMES H. LUMBERS, AND WILLIAMS.GRAY, ALL or roaoN'ro, CANADA,

AS TRUSTEES INTERNAL COMBUSTION E GI E Application filed March 13,1939.Serial No. 436,838.

This invention relates to internal combus- 7 tion engines. Heretoforethe piston in the conventional type of engine has been depended on toclear the burnt gases from the combustion chamber with the result that acertain percentage. of the burnt gases has been left in the combustionchamber at the end of the exhaust stroke of the piston. These burntgases mix with'the fresh charge drawn into the chamber onthe followingsuction or intake stroke of the piston, and decrease the efficiencyofthe engine. My object is to provide simple and inexpensive means toovercome this objectionable feature,-.toincrease the rate of flow andthe volume of the combustible charge drawn into the combustion chamber.of the engine especially at high speeds thereof,to increase the life ofthe lubricating oil carried in the crank case .of the engine,-and toeliminate so-called carbon knocks. i

I attain my objects by interposing'a floating displacement memberbetween the cylinder head and'the top of the piston so that theclearance? volume between the top of the displacement member and thecylinder head will be reduced to a minimum. The burnt gases will thus bethoroughly removed at the end of the exhaust stroke, and the member willbe positioned to draw in a fresh charge immediately the, piston descendson the suction stroke. This will result in an increase inand anacceleration of the partial vacuum created by the descent of the pistonso that a larger volume of the fresh charge will be drawn in, especiallyat high speeds of the I I cngine,:than, is possible with theconventional type of engine. 4

The constructions are hereinafter more fully described and areillustrated in the accompanying drawings in which Fig. 1 is a verticalsection through the cylinder showing the floating displacement member inits position at'the commencement of the suction stroke;

Fig. 2, a section on a reduced scale showing the parts as they arepositioned at the end of the suction stroke;

Fig. 3, a section at the end of the compression stroke just beforeignition takes place;

Fig. l, a sectionsimilar to Fig. 3 at. the end of the compression strokeJust after ignition takes place; and

Fig. 5, a section at the end of the working: stroke, the exhauststrokebeing just about i to commence. V v v a Referring to Figs. 1 to'5,the'engine includes a cylinder ,1, cylinder head 2,1combustion chamber3,intake valve 4, exhaust valve .5," piston 6, wrist pin ,connecting rod8, and crank shaft 91 The upper end of the piston 6 is provided withan'extension 10 which has an inwardly directed lip or flange 11. In theextension "10 is'freciprocably mounted a displacement member12 which iscarried on a stem 13. The stem 13 is slidably carried. in the head ofthe piston 6 and the outer periphery of the member 12is free ofthe innerperiphery of theextension 10. This freedom obviates the necessity oflubri-' .cation between the member 12' and extension 10 and also servesanother purpose as hereinafter set forth. When the member 12comes torest against the lip "11 it makes asubstan-,

tially tight joint therewith. The'lower-en'd of the stem 13 is hollow,and in the wall of the stem is formed ahol'e l l adapted toestablishcommunication between the space within the skirt of the piston and thespace behind the member 12 when'the latter 'is positioned' in engagementwith or near the flange 11. The pressure behindthe member is thusbrought to that of the atmosphere once in each cycle, and therefore anytendency for leakage past theImember to become accumulative is correctedeach cycle. I

A spring 15*bearing against the'wrist pin 7 tends to maintain the member12 in engagement with the flangell. "Assuming the piston 5 to be justcommencing its downward .stroke as shown in Fig. 1, and the intake valve3 to be opening, the

operation is as follows; The displacement member 12 will be eitherresting against. or

i Very nearly resting against the flange 11 and the very small space'between the member and the cylinder head 2 will be the clearance volumeif the engine beconsidered as an air pump instead of the veryconsiderable space between the piston 6*a'nd the cylinder head suction alonger time to draw in the combustible charge. During the suction:strokesthe hole 14 establishes communication between the s ace behindthe=member l2and theatmors p re as hereinbefore described.

gag-Shows the position of the parts at the end of the suction stroke.The space between the member 12.and therc ylinder head 2 'JlS nowfilledwithuncontaminated combustible chhrge and'the space between the memberand the piston 6 is filled with inert gases at atmospheric pressure. Theintake valve 4 is nowjustclosing or is just about to close.

its the iston rises on the compression stroke the resh charge above themember12 will compressed which will result in the member 12be' thepiston 6,'the inertv ases below the member 8 Fi'g.,3ishows therelati'vespositions ofthe parts at the end of the compression stroke.

Ignition then takes place and the pressure above the member 12'risesto amaxn'numralmast and-l the member 12. is forced towards the piston as.ilhistrated in It is to be noted that the fiatnessof the member and ofthe-head of Llthe piston ensures a cushion of'gas betweensthem at alltimes. 7

7111b piston moves down the cylinder during the .WOl'kl stroke and theshereinbeforedesotibedsm annular s cc between the'onter periphery oftheme and th'ednner peof Tthe extensionzwould T ermit a 45 J r I sgixdkage of gasto take place-i there be for any reason arenne'in-pressure. per square inch on the stop, and underside of themember 12. ltfound advisable to cause from above tmbeloWthemember 12during werkinglstrokeandflthis is. aceomplished properly proportioning:the cross section areaiof fthestem13 and the strength of the springlii.

If we consider the member=l2wasin equiat any moment thesum of the forcesacting-to raise it must be equal to the sum of the forces acting topress it down. The

firsfmentioned forces, i. e, those tending to raise'the member, are thegas, pressure on the nndersidofthe member 121'inpounds per squareinchmultiplied bythe area of the underside ofthe member which is exposedtothe'said pressure, and'the upward pressure of "springyl'fi. The forcetending to .snction :intheccylinder tdm'ings, the abo :gi'ves: increasedJ moved towards the-head of mpressedand "e hole 14 beingrclosed.

counteract these forces is the gas pressure on the upper side of themennber 12 in pounds per square inch multiplied by the total area of themember 12. That is to say if we assume that The gas pressure abovemember 12-h lbs. per sq. In. 'I'hegaspresmre below member 12'? lbs; pasq. in.

Total area of marnherlZ-A. Total cross sectional area of stem 13=AzForce of spring l=F Then 1 when member 12'. is any position ofequilibrium P|XA1=P:(A1A1)+F Considering the upward forces (A -A and F,it is evident, since the sum of these two forces has a definite value,that the larger either one is, the smaller the other must be. Thatuistosay if the spring 15 be very strong, the force F will .be sve'rygreat,the force P (A -As) will be very small andrthe pressure P5 consequentlywill Ibe' (small since A A is a constant quantity,

On the other hand,. if the spring; 15 be weak enoughto bernegl igible wewould have the following equation:

Ar-Ar P1 1 I but A is greaterthan' =A --A" and becomes increasinglygreater if A; beincreased. Then P must -"'be greater than 1 andbeoomesincreasingly so if'A bemade greater.- Itis thus possible, byusing astem'j'1'8of small di- 'ameter'and a strong'spring 15, to-mah'e Psstthe of the-combustion chamber, the said member being adapted to reston said flange to close theupper-end of the extension.

Signed at Toronto, Canada, this 19th day of March, 1930.

MAUNSELL B; JACKSON.

